It's his decisions when they need a stop. Stan highlighted quite a few a page back. His plays are too conservative at the wrong time. His situational football is shyt.
Now, some if not all of it, may have been Harbaugh's doing, but look at that Squeelers game when AB reached his arm over the endzone and they beat the Ravens for the division if I'm not mistaken. Pees had CBs giving absurd 10-12 yard cushions and they just marched down the field dinking and donking til they scored. Pees always did this when the corners should've been playing up close to jam the receivers, which throws off timing and allows the passrush to get to the QB.
The bad
timing cover 0s is something he did alot of too. That's been pretty constant with any DC since Harbaugh's been here. Orr was guilty of it last week, but Burrow didn't take advantage.